1. Field of the Invention
The present invention relates in general to valves and more particularly to electromagnetic valves used for controlling a fluid flow.
2. Description of the Prior Art
In order to clarify the task of the present invention, one conventional electromagnetic valve disclosed in Japanese Utility Model First Provisional Publication 58-172166 will be outlined prior to making a detailed description of the invention.
In the conventional valve, there is provided a port structure which has a port formed therethrough. The port is selectively closed and opened by a valve body which is carried on an armature. The armature is pivotally mounted on a yoke. An electromagnet is mounted on the yoke to pivot the armature in response to ON/OFF operation thereof. Thus, in response to the ON/OFF operation of the electromagnet, the valve body on the armature closes and opens the port selectively.
However, hitherto, a so-called "multiple valve structure" for the above-mentioned conventional valve has been given little thought. In fact, if two valve functions are needed in a fluid flow control system, two independent electromagnetic valves must be prepared for such system. As is known, using a plurality of independent valves in the system causes not only a bulky and heavy construction of the system but also a troublesome and time-consumed assembling work for the system. An exemplified fluid control system which uses two independent electromagnetic valves is shown in page B-93 of "Service Manual, Volume 628" issued from NISSAN MOTOR CO., LTD July 1989. In this system, the two valves are used as an air control valve and a relief valve respectively.